In some situations sensors/actuators that are not normally intended for use in hearing aids may advantageously be applied within hearing aids. Such sensors/actuators typically require a supply voltage that is higher than 1.5 Volt which is the typical supply voltage in hearing aids (ZnO battery).
Typically sensors/actuators are designed for use with Li-Ion rechargeable batteries, which means that such devices work in a range of 1.7 to 5 volts. Moreover, other hearing aid building blocks, such as preamplifiers in microphones, may reach a higher dynamic range if a higher supply voltage is available. In addition, A/D converters or other mixed signal building blocks and possibly bias voltages for (silicon) microphones may take advantage of a higher supply voltage level.
It may be seen as an object of embodiments of the present invention to provide a DC voltage source having a supply voltage level exceeding 1.5 Volt with minimum use of extra circuitry.
It may be seen as a further object of embodiments of the present invention to provide a DC voltage source suitable for applications in hearing aids.